Dieless Friction Stir Extrusion-Brazing (DFSE-B) of AA2024-T3 aluminum alloy to Copper with Zn interlayer

• Published in: Results in physics Vol. 24; p. 104101
• Main Authors: Paidar, M., Mohanavel, V., Ojo, O.O., Mehrez, S., Rajkumar, S., Ravichandran, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2021; Elsevier
• Subjects: AA2024 aluminium alloy; Copper alloy; Dieless Friction Stir Extrusion-Brazing; Friction Stir Spot Welding-Brazing; Mechanical properties; Microstructure; Mechanical properties; Friction Stir Spot Welding-Brazing; AA2024 aluminium alloy; Microstructure; Dieless Friction Stir Extrusion-Brazing; Copper alloy
• ISSN: 2211-3797; 2211-3797
• DOI: 10.1016/j.rinp.2021.104101

•For the first time, dissimilar Die Friction stir Extrusion-brazing (DFSE-B) of AA2024 to Copper was conducted using Zn interlayer.•Zn interlayer changed the type of IMCs at the Al/Cu joint.•Maximum tensile shear loads of the DFSE-B and FSSW-B joints are 4029 and 3009 N respectively due to the mechanical interlocking of the softer Al alloy into the prefabricated (through) hole in the DFSE-B joint.•Both joints fail by ductile fracture mode. The integration of flow-induced mechanical interlocking, interlayer-controlled atomic diffusion and self-reacting brazing benefit is employed to achieve an improved load-bearing performance of the dissimilar AA2024-T3/copper joint via the use of Dieless Friction Stir Extrusion-Brazing (DFSE-B). A comparative study of the Dieless Friction Stir Extrusion-Brazing (DFSE-B) and Friction Stir Spot Welding-Brazing (FSSW-B) of the dissimilar AA2024-T3/Cu joint was investigated by using a 100 µm thick Zn interlayer. The microstructure, tensile-shear load, and fracture modes of the respective joints were examined. The results show that Zn solidification-induced voids are inevitable at the brazed zones of both joints and the DFSE-B process suppresses flow-induced defect, unlike the FSSW-B process. An improved tensile-shear load with a significant toughness is achieved by the DFSE-B process due to the absence of tool-induced keyhole, and the intrinsic mechanical interlocking of the softer Al alloy into the harder Cu alloy. The DFSE-B is a suitable welding alternative for reactive metals.